1. Technical Field
The invention relates generally to color changing inks.
2. Brief Description of Related Technology
Eradicable ink systems generally include two components. One component is an aqueous ink that includes a dye—typically a triarylmethane—that can be rendered substantially colorless when contacted with a substance such as a sulfite reducing agent or an amine. The second component is an aqueous eradicator fluid that includes a substance that can cause a complementary dye to convert to a substantially colorless form. A user writes with the ink and, if correction is necessary, applies the eradicator fluid to the ink marking to decolorize the dye.
Highlighting a marking is typically performed using a fluorescent ink applied over a regular marking made by an ink on a substrate (e.g., paper). A typical fluorescent highlighting ink has a translucent quality to allow for a user to apply the highlight ink and yet still see the regular ink marking under the fluorescent ink marking made by the marker. While this process serves to highlight a regular ink marking, it also has the undesirable effect of highlighting areas of the substrate that do not include a regular ink marking.